Sulphocarboxylic esters



ensures an is, test I 2,168,145 SULPHOCARBOXYHG ESTERS amin E. Harris, Chicago, 111.

No Drawing. @riginal application November 1937, Serial No. 174,655. Divided and this application September 23, 1938, Serial No. 231,367

Claims.

ally used in relatively small quantities but capa- 1o ble of use in larger quantities to secure an effect principally the result of a wetting action such as at a water-oil interface. In the textile anddyeing industries, for example, there are many situations where a wetting or detergent action is im- 15 perative as, forexample, in laundering, bleach:-

ing, mercerizing, dyeing or other operations, and many different chemical substances have been produced calculated to reduce surface tension and promote wetting in these industries. The use of prior art substances has not been attended with unqualified success in all instances. In certain other types of industries, such as the margarine industries, for example, problems in preventing the spattering of margarine in frying have arisen. These problems are considered by some investigators as entirely a matter of wetting; in other words, by promoting greater attraction between the oleaginous and aqueous portions of the emulsion at the interfaces thereof. Although the problem is probably not one of wetting action entirely, it appears that certain compounds which in theory tend to concentrate at the water-oil interface have an effect upon the spattering behavior or" margarine. This probleni is discussed and a remedy disclosed in my prior application, Serial No. 566,156, .flled September 30, 1931, now Patent No. 1,917,256, as a continuation-in-part of a prior application, Serial No. 475,622, new Patent No. 1,917,250.

The principal object of my present invention is the provision of a new class of chemical substances capable of satisfactory use in connection with the problems hereinabove discussed..-

1 Another object is the provision of a new' class of chemical substances which are in general of relatively simple structure and can be cheaply made in commercial quantities.

Another object is the provision of a class of chemical substances of the character set forth to which in the main will be innocuous and nontoxic, even though employed in such foods as margarine.

Another object is the provision of a new class of chemical substances having improved wetting characteristics.

Other objects and features of the invention will be apparent from a consideration of the'iollowa ing detailed description.

The substances of my invention are in seneral ester derivatives of lower molecular weight fatty acids with at least one: unesterifled sulphonic acid group in the fatty acid radical where- 10 f in the group ,esterified with the fatty acid has a hpophlle radical with at least iour carbon atoms. In certain circumstances there may be more than one unesterifled sulphonic acid group in the fatty acid radical or there may be sulphonic acid 15 groups that are esterified and other sulphonic acid. groups that are not esterificd, but in all cases there must be at least one unesterified su1- phonic acid group in the fatty acid radical. The fatty acid radical with the free sulphonic acid 20. group is of relatively low molecular weight and should contain not more than eight carbons.

Considering the compounds from another aspect, the molecule in each instance contains a lipophile group having at least four carbon atoms.25

and a relatively low molecular weight hydrophile group which, in the class of compounds to which my present invention relates, are sulpho-carboxylic or sulpho-fatty acid radicals. From still another angle, the-compounds may be considered 30 as combinations of a lipophile group having at least four carbon atoms and a relatively low molecular weight sulpho-carboxylic or suipho-fatty acid group. A more complete understanding or what may comprise the lipophile group and the as particular character of the sulpho-carboxylic or sulpho-fa'tty acid group will be had as the detailed description progresses.

The function of the sulphonic acid group is to impart hydrophilic properties, that is, water wet 40 ting or water attracting properties, to the molecule as a. whole. The groups which are esteriiled by the sulpho-carboxylic or sulpho-fatty acid are in general of a lipophile character. At 45 times they may be strongly lipophilic and at other times moderately lipophilic. They may be of low molecular weightor of moderately high molecular weight, depending upon the purpose for which the substances may be used. 4

The substances of my invention with which my present application is concerned are lower mo lecular weight sulpho-carboxylic acid esters oi ethers and esters of polyhydroxy substances wherein the ether or ester radical contains at least four carbon atoms and preferably between eight and eighteen carbon atoms. Various examples or compounds falling within the scope of my invention are as follows:

0 Hr-C-O-L-Crflis H- --O--C,|Hu 0 Hr- OC-CH1 =0 v No Cetyl ether of monostearln sulphoaeetate (sodium salt) Monolaurin sulphoacetate (sodium salt) Monopalmitin sulphobutyrate (sodium salt) I 1 HeC-O-JJ-CuHu Mono-palmitic acid ester oi ethylmeglyeol sulphopropionate (sodium salt) Dl-sulphoeoeflo Mid ester or mono-olein (disodium salt) Mono-polmitic acid enter 0! tri-methylene glycol sulpholcetate sodium-salt) c-steerie, pbenzoic, a-sulphoaceltti)c acid ester of glycerin (sodium a-Stearlc, fi-(p-sulphethoty) benzolc, asulphopropionic acid ester of glycerin ONa Monostearic acid ester of diethys'fige glycol sulpho-acetate (sodium Mouo-oleic acid ester of diethygfize glycol sulphoacetate (sodium n CH:OCUnHu CH-OH 0 CHr-OCCH:S=O

ONa Monostearln sulphoacetate (sodium salt) Stearyl glycerol sulphoaoetate (potassium salt) I may select many difierent types of compounds as lipophile groups, particularly those having at least eight carbon atoms although, i'or some purposes, the lipophile group or groups may contain as low as four carbon atoms. lbr example, the following compounds may be utilized as sources of lipophile groups, andaulpho-carboxylic acid esters thereof such as sulphoacetates may be prepared therefrom by procedures described more fully hereinafter: butyl alcohol,

amyl alcohol, hexyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, oleyl alcohol, stearyl alcohol, ricinoleyl alcohol, palmitoleyl alcohol,

- such as abietol.

, cohol, myricyl alcohol, and, in general, the higher molecular weight saturated and unsaturated aliphatic alcohols. I may also employ cycloaliphatic or all-cyclic alcohols such as the sterols, as, for example, cholesterol, iso-cholesterol, phytosterol, as well as hydro-aromatic alcohols In addition, I may utilize such unsaturated alcohols as linalool, citronellol, geraniol and the like. It is, of course, obvious that the alcohols may be prepared in accordance with any desired method. For example, these.

alcohols may be prepared by the so-called Bouveault and Blanc method or, alternatively, by the reduction or catalytic reduction with hydrogen of natural or hydrogenated animal or vegetable fats and oils in accordance with well known practices. Again, the alcohols may be derived from synthetic processes such as by the oxidation of hydrocarbons or may be prepared by saponification of waxes and the like. Alternatively, they may be prepared by reduction of aldehydes or by the Grignard reaction. Still other methods known in the literature may likewise be employed if desired or deemed expedient. It is likewise apparent that mixtures of the foregoing or other alcohols may be utilized as, for example, the mixture of alcohols resulting from the hydrogenation of coconut oilor the free fatty acids of coconut oil. Lauryl alcohol'comprises about of the total alcohol mixture, the remaining alcohols running from C6 to C18. The sulpho-carboxylic esters of these mixtures of alcohols function in substantially the identical manner as the sulpho-carboxylic acid esters of the substantially pure alcohols. Again, mixtures of alcohols such as are present in the so-called sperm oil alcohols, as well as those present inwool-fat, may equally eflicaciously be utilized. Indeed, these higher molecular weight alcohols are generally, if, indeed, not almost invariably, ofiered on the market in the form of mixtures of difierent alcohols. If desired for any specific purpose, special fractions which predominate in a certain particular higher molecular weight alcohol may be utilized or, if so desired, the sulpho-carboxylic esters may be prepared from a single, substantially pure alcohol. The source of the higher molecular alcohols which may be utilized in the preparation of my sulpho-carboxylic esters is entirely immaterial.

I may select many difl'erent types of compounds as lipophile groups which are to be esterifled oretherifled with the polyhydroxy substances,

principally compounds having lipophile radicals of relatively high molecular weight. For example, the following materials maybe utilized as sources of lipophile groups: carboxylic or fatty acids such as butyric acid, caprylic acid,

caproic acid, capric acid, saturated and unsaturated higher molecular weight aliphatic acids such as the higher fatty acids containing at least eight carbon atoms and including melissic acid, stearic acid, oleic acid, ricinoleic acid, linoleic acid, lauric acid, myristic acid, palmitic acid, mixed higher fatty acids derived from animal or vegetable sources, fonexampla-lard, coconut oil, sesame oil, corn oil, cottonseed oil, sardine oil,

partially or completely hydrogenated animal and vegetable oils such as those mentioned, fatty acids derived from various waxes such as beeswax, spermaceti, montan wax, and carnauba wax and carboxylic acids derived, by oxidation and other methods, from petroleum, hydroaromatic acids aromatic acids such as benzoic acid, naphthoic' acid, and the like.

The polyhydroxy substance which provides the linkage between the lipophile group and the sulpho-carboxylic group may be selected from a large class and includes glycerol; glycols such as ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol and the like; polyglycols such as diethylene glycol; polyglycerols such as diglycerol, triglycerol, tetraglycerol and the like including mixtures thereof; sugars such as dextrose, sucrose, xylose, galactose, fructose, maltose, mannose and the like; sugar alcohols such as arabitol, mannitol, sorbitol and dulcitol; and polyhydroxy-carboxylic acids! such as tartaric acid, mucic acid, saccharic acid, gluconic acid, glucuronic acid, gulonic acid, mannonic acid, trihydroxyglutaricacid, glyceric acid, carboxylic oxidation products of polyglycerols, others of similar character, and hydroxyethyl and hydroxypropyl' ether derivatives of the above, as for example:

' H1C-OCH:-CH;OH

HC-O-CHz-CHaOH H C-O-CHg-CH OH HsC I,

nc i-o-cnf-cmon mo-o-cm-omon not be an ester linkage, although such is preferred, but it may be an ether linkage, as illustrated by compounds numbered (12) (13), (14) and (15) hereinabove.

From a' study of the compounds which I list' hereinabove, those skilled in the art will understand that I may use many different expedients for forming the compounds in so far as the dominant lipophile group and the relatively low molecular weight sulpho-fatty acid group are concerned. As stated, however, ester linkages are utilized between these two portions of the compound, and the skilled chemist will'understand in general the most approved practices in securing this result. Numerous methods are also available for the introduction of the sulphonic acid group. In the case of aromatic sul-- phonic acids, of course, standard sulphonation; procedures employed for producing aromatic sulphonic acids may be used, and, if desired, the lipophile group may be introduced subsequently.

In the case of aliphatic sulphonic acids, and, forthat matter, even for the production of aromatic sulphonic acids, a reactive halogen may be caused to react with sodium sulphite or potassium sulphite or ammonium sulphite or some I other sulphite in aqueous solution, if desired.

Another method is to introduce a sulphhydryl or disulphide or some other suitable sulphur groupand then oxidize to the sulphonic acid with nitric acid or a permanganate or some other oxidizing agent.

Still other methods will suggest themselves to .the skilled chemist. Thus, for example, one or more esterifiable hydroxyl groups of a polyhydroxy derivative may be caused to react, under suitable conditions, with sulpho-acyl halides such as are represented by the formula:

wherein X is halogen, particularly chlorine 'or bromine, and n'is a small whole number, at least one. The sulpho-acyl halides may also be of the type wherein the sulphonic group is attached to an intermediate carbon instead of to the terminal carbon as illustrated above.

Another method which may also be employed to produce the compounds of my invention involves reacting a polyhydroxy compound or derivative thereof, there being at least one free hydroxy'group present in the polyhydroxy nucleus, with a sulpho-acyl anhydride the sulphonic group of which may be attached to either the terminal or an intermediate carbon atom of the sulpho-acyl anhydride.

My preferred process comprises reacting upon one or more free or esterifiable hydroxy groups of a polyhydroxy substance, or derivative of a polyhydroxy substance, with a halogeno-carboxylic acid such as chloracetic or bromacetic acid,

or with a halogeno-carboxylic acid halide such as chloracetyl chloride or brom-acetyl bromide, to form a chloracetate or bromacetate, and then converting the latter into the sulphonic acid derivative by reaction with an alkali metal sulphite.

The following examples are illustrative of the preparation of compounds falling within the scope of my invention. It will be understood that said examples are given only by way of illustration and are not to be considered in any way limitative of the true scope of my invention.

Exmts I.M01l0stearine sulphoacetate, Na salt (a) 700 parts of monostearine were heated with 175 parts of chloracetic acid for 3 hours at a temperature of 150-160 degrees C. in an atmosphere of CO2 and with agitation. The reaction product was washed free of chloracetic acid with 4 times its own volume of water at degrees C. and, to assist in separation, parts of salt were added to the wash water. i (b) The product obtained in (a) was mixed with 500 parts of water, heated to about 60 degrees C., and then 175 parts of sodium sulphite were added. The temperature was maintained at 60-75 degrees C. with constant stirring for the first hour, then raised to 90-95 degrees C. and kept at that temperature for. about threequarters of an hour.

(c) To remove excess sulphite and other objectionable impurities, the product obtained in (b) was dispersed in 8 times its own volume of water at 80 degrees C., salted out with about 10% salt, allowed to settle and the wash water water was obtained. The water may. be elimi-- nated in any desired manner to produce a dry product.

'Exnnmr. IL-Distearine sulphoac etate 400 parts of pure monostearine sulpho a cetate were heated with 300 parts of stearyl chloride in 500 parts benzol at a temperature of 80-100 degrees C. until no further evolution of hydrochloric acid could be observed. The excess ben-' EXAMPLE III.-Distearine sulphoacetate, K salt 200 parts of distearine were heated with 65 parts of chloracetic acid for 3 hours at 160-170 degrees C. When the reaction was completed the product was washed free of chloracetic acid and dried.

(b) 50 parts of the product obtained in (a) were mixed with 25 parts of potassium sulphite dis olved in 35 parts of water. 2 parts of potassium iodide were added and the mixture stirred and heated for about 10 hours on a water bath at 60-70 degrees C. and about 2 hours at 75-80 degrees C. a

(c) To remove excess sulphite, 50 parts of the product obtained in (b) were dispersed in 500 parts of water, heated to 80 degrees C., and then salted out with 15% salt. The washing process was repeated several times. A paste containing about 50% water was obtained.

(d) For further purification, parts of isopropyi alcohol were added to 10 parts of the paste, the mixture brought to the boiling point and filtered hot. The filtrate was allowed to cool and the precipitate that came down filtered oil, washed several times with ether and then dried at room temperature. The product obtained dispersed readily in hot water.

Exmu: IV.M0nostearine disurphoacetate, K salt stirred and heated on a water bath for about 8 hours at 70-80 degrees C.

' (c) The product obtained in (b) was dispersed in 400 parts of water at 60-70 degrees C. and the dispersion saturated with sodium chloride. Very little separation took place. On chilling in an ice bath to 10 degrees C., the product could be isolated by gravity filtration. The process of dispersion, saturating with salt, chilling and gravity filtration was repeated a second and third time.

A white paste containing about 50% water was obtained.

(d) To further purify the product obtained in (c) 10 parts of the latter were dispersed in 10 parts of water. 80 parts of hot isopropyl alcohol were added and the mixture brought to the boiling point and then filtered hot. On cooling and arcane by the addition of a little more isopropyl alcohol, the sulphoacetate was precipitated. The precipitate was filtered oil and dried at room temperature.

Examms V. M0nostearic acid ester of diethylene glycol sulphoacetate, K salt (a) 500 parts of diethylene glycol monostearate, prepared by heating a mixture of one part of stearic acid with one'part of diethylene glycol at a temperature of about 220 degrees C., using 0.1% KOH, until the free fatty acid content is down to about V to 1%, was heated with 2501 parts of chloracetlc'acid at 160-170 degrees C.

for 4 hours; The product was washed free. of chloracetic acid and dried.

(b)- 50 parts of the product obtained in (a) were mixed with 35 parts of potassium sulphite and 50- parts water. 2 parts of potassium iodide were added and the mixture stirredand heated for about hours at '70-'75 degrees C. At the end of the 10 hours, 800 parts of hot isopropyl alcohol were added, the mixture brought to the boiling point and filtered hot. The alcohol solution was allowed to cool. The product was obtained in the form of a precipitate consisting of crystals of grayish leaflets. These dissolved readily in hot water. I

F sarrrs VI.- -Cocosut mono fatty acid esters of diethylene glycol sulphoacetate, K salt 7 (a) 400 parts of the fatty acid mono esters of diethylene glycol with mixed coconut oil fatty acids were heated with 260 parts or chloractic acid 1on3 hours of 160 degrees C. using a stream of CO2 for agitation and removal of moisture.

(b) 200 parts of the washed and dried product obtained in (a) were mixed with 130 parts of l potassium sulphite and 200 parts of water. 4 parts of potassium iodide were added and the mixture stirred and heated on a water bath at 60-70 degrees C. for about 10 hours. The. re-

- action product was then dispersed in about 8 times its own volume of water heated to 60-70 degrees C. and salted outwith salt. The washing was repeated a second and third time. A thin paste, light in color and containing 60% water was obtained.

(c) The product may be used as finally ob-' tained in (b) or may be purified by heating to the boiling point with 8 volumes of isopropyl alcohol, filtering hot and, allowing the alcoholsolution to cool. The precipitate which comes down is filtered ofi and dried at room temperature. The filtrate may be evaporated to dryness to recover the alcohol soluble substances.

EXAMPLE VILs-Mono-lauryl glycerol sulphoacedrochlorlc acid, was then mixed with 1000 grams tate, Na salt (a) 115 grams of glycerin mono-chlorhydrin were mixed with 210 grams of sodium lauryl'ate (CiaHnONa) and the mixture was maintained at between 75 degrees C. and 85 degrees C. unti ,mono-lauryl glycerol was formed.

(b) About 250 grams of theresultin g ether,

washed free of sodium chloride if desired, was then. mixed with 130 grams of chloracetyl chloride,

the latter being added dropwise at about 38 de-' grees C. to 40 degrees C. (c) The resulting product, washed free of hyof sodium sulphite dissolved in 5000'cc. of water and heated to between '75 degrees C. and 85 de-- grees C. for one and one-hall hours with constant stirring. I k

molecular -weight polyhydric alcohol.

was recovered in purified form in substantially the same manner as described in the aboveexamples.

Exmm VIII-Cetyl ethylene glycol sulphoacetate,-K salt 36 grams of the cetyl ether of ethylene glycol chloracetate' (C|sHa-OCHr-CH -OOICHQOI) were mixed with 55 grams or potassium sulphlte dissolved-in 275 cc. of water and the mixture was heatedat 85 degrees C. for about one and onehalf hours.

The resulting product was freed of potassium chloride in substantially the manner set forth in the above examples. I

Those 'smlled in the art are referred to my PatentNo. 1,917,260, in which I disclose the use of some of the compounds of my present invention as'anti-spattering agents for use in margarine. In thispatent, I also treat of the man-- net of mamng'some of these compounds.

Those of my substances which are freely soluble in water may be recovered from their solutions and from their water solutions in the customary manner by-concentrating and crystallizing. As stated hereinabove, as the mass of the lipophile radical increases. solubility decreases and amnity for water is manifested by the dispersibility in water. From these dispersions, my substances may be readily recovered by "salting out" with suitable soluble electrolytes. Common salt is very satisfactory for this purpose in most cases. when salted out or an aqueous dispersion at temperatures ranging from 60 to 95 degrees C., the substances are obtained in the form of a pate with a water content ranging from approximately 25 to 75%. The more hydrophilic the substance, the greater the water. content,

and, of course, the salt is present in the'water of the pastein approximately the same concentration in whichit existed in the dispersion from which the paste was salted out;

Many of the compounds of my invention may be represented by the general formula wherein R denotes a lower molecular weight aliphatic radical containing at least one sulphonic acid radical and R1 denotes a; radical of a higher In one specific aspect, R1 may be the radical of a polyhydric aliphatic alcohol in which a group selected I from the class consisting of acyl and alkyl groups displaces the hydrogen of one hydroxyl group of the polyhydric alcohol, the total number of carbon atoms in the final alcohol molecule being greater than 8. I

Many of the compounds or my invention may also be represented by'the general f0 ula wherein a is a polyhydric alcohol radical con:

wherein R is the residue of a polyhydroxy substance in which the hydrogen of at least one hydroxyl group is substituted by an alkyl or acyl group containing at least four carbon atoms and preferably between eight and eighteen carbon atoms, X is the carbon-hydrogen residue of the sulpho-carboxylic acid, Y is a cation, and w is a small whole number, at least one.

I have previously referred to the fact that the lipophile group may-in itself contain hydrophile radicals. For example, in the case of monostearin sulphoacetate, the hydroxy radical of the second glycerine carbon has a recognized hydrophilic character. The group as a whole, however, of which this hydroxy radical is a part, is dominantly lipophile, the single hydroxy radical in such a compound being insufficient to impart dominant hydrophile characteristics to the group as a whole. Moreover, in the case of a compound having an esterified sulphonic acid. group, this sulphonic acid group will usually be- In so far as the sulpho-carboxylic or sulpho-.

fatty acid group of my compounds is concerned, I mayemploy a sulpho-acetate, sulpho-propionate, sulpho-butyrate, or other similar groups containing an unesterified sulphonic acid radical 'and, generally, not more than seven carbonatoms. In general, however, I have found that the sulphoacetates particularly produce coinpounds of exceptionally valuable characteristics and they have the advantage ofbeing relatively inexpensively produced from commercially available substances.

The terms "sulpho-carboxylic acid and "sulpho fatty acid as employed throughout the specification and claims are used in a strictly rigorous sensevto mean a compound which contains at least one o '-c-s:0.

group. The numerous examples given are clear in this feature.

In the event that the compounds of my invention are made by reacting the halogen derivatives with alkali metal or ammonium sulphites or other soluble sulphites as well as thiosulpbates, the corresponding alkali metal or ammonium sulphonic acid derivative will be produced. when prepared by other methods sot-hat the compounds contain the sulphonic acid group (-SOaH), the. hydrogen'thereof may be replaced by other cations such as calcium, magnesium, aluminum, zinc, amines, alkylolamines such as mono-, diand triethanolamine and mixtures thereof, other organic nitrogenous bases such as pyridine and piperidine, tertiary amines, quaternary ammonium bases, etc. It will be understood that by the term "cation", as used throughout the specification and claims, is meant hydrogen and such other elements as are mentioned herein, and, in general, atoms or radicals which are regarded as bearing a positive charge or capable of replacing acidic hydrogen.

It will be understood that the selection of the particular halogen derivatives which are utilized in the preparation of the halogen-carboxylic acid ester intermediate products will depend upon certain factors. Thus, while bromoand iododerivatives, in general, react slightly more rapidly than do the chloroderivatives, the relatively cheaper cost of the latter will generally justify their use from apurely economic stand- Point.

The term residue, as used throughout the specification and claims, is employed in its ordinarily'understood chemical significance. For exis the "residue of the polyhydroxy substance, in this case glycerine.

Similarly, the term carbon-hydrogen residue of a sulpho-carboxylicg acid 'is employed as in conventional chemical nomenclature. Thus, for example, if sulpho-aoetic acid is esterified with glycerine, the group CH:- is

to be considered as the carbon-hydrogen resi due of the sulpho-acetic acid.

It will be understood that the term lipophile group, as employed herein, is intended to cover any radical containing at least four carbon atoms and having an afiinity for oleaginous material such as oils, fats, hydrocarbons and the like and may comprise radicals such as hydrocarbon radicals, acyl or alkyl groups derived from aliphatic or fatty acids or' their corresponding alcohols, and the like. The hydrophile group or groups, in other words, the groups having an afiinity for aqueous materials are, as fully set forth hereinabove, sulpho-carbomlic fatty acid groups.

Unless otherwise indicated, the term "higher", wherever employed in the claims, will be understood to mean at least eight carbon atoms and, concomitantly, the term "lower" will mean less than eight carbon atoms.

Whenever the term sulpho-carboxylic ester, sulpho-aoetate, or .the like expression is employed in the claims, it will be understood to cover the compounds irrespective of whether the hydrogen or sulphoof the sulphonic acid is present as such or replaced by another cation.

My present application is a division of mycopending application, Serial No. 174,655, filed November 15, 1937, and is directed specifically to those of my sulpho-carboxylic acid esters which are derivatives of poiyhydroxy substances.

What I claim as new and desire to protect by Letters Patent of the United States is:

1., A sulpho-acetate of a glycol wherein the hydrogen of one hydroxyl group of the glycol is substituted by a straight chain higher molecular weight aliphatic radical.

2. A derivative of a lower molecular weight polyhydric alcohol, the hydrogen of only one hydroxyl group of which is substituted by a sulphoacetic acid radical, and a hydrogen of only one hydroxyl group of the polyhydric alcohol is substituted by a straight chain higher molecular weight aliphatic radical containing eighteen carbon atoms.

3.'A chemical compound corresponding to the formula group of which is replaced by a high molecular weight straight chain aliphatic radical.

5. A sulpho-acetate of a lower molecular weight polyhydric alcohol wherein the hydrogen of one hydroxyl group of the polyhydric alcohol a is substituted by a straight chain aliphatic radical containing at least four carbon atoms.

6; A derivative of a lower molecular weight polyhydric alcohol, the hydrogen of only one hydroxyl group of which is substituted by a sulphoacetic acid radical, and a hydrogen of only one hydroxyl group of the polyhydric alcohol is substituted by a straight chain aliphatic radical containing at least four carbon atoms.

7. A chemical compound corresponding to the formula 0 LCCH:S:0

wherein Y is a cation selected from the group consisting of alkali metals and ammonium, and L is a tri-hydric alcohol radical in which the hydrogen of one hydroxyl group is substituted by a higher molecular weight straight chain aliphatic radical.

8. A carboxylic ester of a relatively low molecular weight sulpho-fatty acid with one master-- ifled sulphonic acid group, wherein the radical esterifled with the sulpho-fatty acid is a glycol radical the hydrogen of one hydroxy group of which is replacedby a high molecular weight straight chain aliphatic radical.

9. A lower molecular weight sulpho-carboxylic acid ester of an ether derivative of an aliphatic polyhydroxy-substance wherein-the group etherified with the polyhydroxy substance comprises a lipophile group with at least four carbon atoms.

10. A process of preparing sulpho-carboxylic acid esters which comprises esterii'ying a compound in the form of an ether of a higher molecular weight alcohol with a polyhydroxy sub.- stance, said ether containing atleast one-free hydroxy group attached to the polyhydroxy nucleus, by means of a member selected from the and acyl halides thereof, and then reacting the resulting compound with a sulphite selected from the group consisting of alkali metal and ammonium sulphites.

11. A carboxylic acid ester of a lower molecular weight sulpho-fatty acid and a glyc'erol derivative, said glycerol derivative containing atleast one free glycerol hydroxy group and comprising glycerin in which the hydrogen of at least one hydroxy group is replaced by an aliphatic radical containingat least four carbon atoms, the sulphofatty acid radical containing at least one unesterified sulphonic acid group.

12. A carboirylic acid ester of a lower molecular weight sulpho-fatty acid and a glycol derivative, said glycol derivative containing one free glycol hydroxy group and comprising a glycol in which the hydrogen of one hydroxy group is replaced by a higher molecular weight aliphatic radical,

a group selected from the class consisting of acyl and alkyl groups displaces the hydrogen of one hydroxyl group of the polyhydric alcohol, the total number of carbon atoms in the final alcohol molecule being greater than 8.

14. A carboxylic ester of a lower molecular weight sulpho-carboxylic acid and a glycol derivative, said glycol derivative containing one free glycol hydroxy group and comprising a glycol in which the hydrogen of one hydroxy group is replaced by a lipophile group containing at least eight carbon atoms, a sulphonic acid group of said' sulpho-carboxylic acid being unesterified.

15. A process for the preparation of lower molecular weight sulpho-carboxylic esters which comprises esterifying an aliphatic polyhydroxy substance, wherein there is present at least one free hydroxy group on the polyhydroxy substance and wherein the hydrogen of at least one hydroxy group of the aliphatic polyhydroxy substance is replaced by a lipophile group containing at least four carbon atoms, with a member selected from the group consisting of lower molecular weight halogeno-carboxylic acids and derivatives thereof eralformula (RO)u--X(-OH)w wherein R is a lipophile group containingat least four carbon atoms, X is the carbon-hydrogen residue of an aliphatic polyhydroxy substance, and v and w are small whole numbers, at least one, with a member selected from the group consisting of lower molecular weight halogen-containing aliphatic carboxylic acids and acyl halides thereof whereby aihalogen-containing ester is produced, and then reacting the resulting ester with a sulphite selected from the group consisting of alkali metal and ammonium sulphites whereby "hers of the group consisting of chlor-acetic acid,

brom-acetic acid, chlor-acetyl chloride and brom-, acetyl bromide.

18. A lower molecular weight sulpho-carboxylic acid ester of an aliphatic polyhydroxy substance wherein the hydrogen of at least one hydroxy group of the polyhydroxy substance is replaced by a lipophile group having at least four carbon atoms. I

19. A lower molecular weight sulpho-carboxylic acid ester of a water soluble aliphatic polyhydric alcohol wherein the hydrogen of at least one hydroxy group of said aliphatic polyhydric alcohol is replaced by an aliphatic group containing from 8 to 18 carbon atoms.

20. A lower molecular weight sulpho-carboxylic acid ester of an aliphatic polyhydroxy substance wherein the hydrogen of at least one hydroxy group of the polyhydroxy substance is replaced ,by a lipophile group containing at least eight 

